PC/104 - USB Isolated I/O
USB-IIRO4-2SM - USB Isolated I/O and Serial Communication Board
• Multifunction I/O adapter for USB 1.1 and 2.0 port hosts
• Four optically isolated digital inputs
• Four Form C electromechanical 1A relays
• Two serial ports, field selectable RS-232/422/485
• Small (4"x4"X1.8") rugged industrial enclosure
• PC/104 module size and mounting compatibility
• All required power drawn from USB port, no external power
adapter required
• Expansion USB hub port connector
• Type B USB connector features industrial strength and highretention design
• Four digital input/output version (USB-IIRO-4DB) available
• Two serial ports only version
• OEM (board only) version with PC/104 mounting holes and PCB
footprint for added flexibility in embedded applications
• DIN rail mounting for industrial environments
• RoHS Available. Please contact us for ordering information
The USB-IIRO4-2SM is a USB multifunction device, incorporating a USB 4-port hub internally to provide four optically isolated digital inputs,
four electromechanical relay outputs and two ports of RS-232/422/485 serial communication in one small product. The digital portion is ideal
for adding easy-to-install isolated input and relay output capabilities to any PC or embedded system with a USB port. This single USB multifunction device is ideal for a variety of applications such as industrial monitoring, control and communication.
The isolated, non-polarized inputs may be driven by either DC sources of 3-31 V (or higher by special order) or AC sources at frequencies of
40Hz to 10kHz. Optically isolating the digital inputs from each other, and from the computer, assures smooth, error-free data transmission in
noisy, real-world environments. The relay outputs are de-energized at power-up to prevent an unintended control output signal. Data to the
relays is latched. The relay contacts and isolated inputs are available via a mounted DB25 connector or, for OEMs, a 26-pin IDC type vertical
keyed shrouded header. For testing purposes and low current applications 5VDC and ground pins are provided on the same connector. The
digital portion of the USB-IIRO4-2SM is excellent in applications where only a few on-board relays are required and a small number of inputs
must be isolated such as in test equipment, instrumentation and process control.
The serial section is a two-port asynchronous serial communication adapter designed for use with any computer system equipped with a USB
port. Multiple peripherals such as POS, barcode scanners, scales, date-entry terminals, data acquisition modules, and automation equipment
can now be recognized and used on a single USB port. Simply install the included software and connect the unit to your USB port. It instantly
provides two RS-232, RS-422, or RS-485 serial ports which can be selected on a port by port basis. It is now easier than ever to add serial
ports and serial devices to any application along with easy plug-and-play and hot-swapping features.
Advanced Digital Logic, Inc.; 4411 Morena Blvd., Suite 101; San Diego, CA 92117-4345
Ph. 858 490-0597 F. 858 490-0599; e-mail: [email protected]; web:
PC/104 - USB Isolated I/O
Type FT232 UARTs are used as asynchronous communication elements. This includes 384-byte receive / 128-byte transmit FIFO buffers for
high data throughput and to protect against lost data in multitasking systems. Crystal oscillators located on the card permit precise baud rate
capability up to 230.4K for use in RS-232 mode, using ICL3243 type drivers. Speeds up to 921.6K are achievable using RS-422 & RS-485.
The driver/receivers used are type SP491 which are capable of driving long communication lines at high baud rates. They can drive up to ±60
mA on balanced lines and receive inputs as low as 200 mV differential signal superimposed on common mode noise of +12V to -7V. In case
of communication conflict, the driver/receivers feature thermal shutdown. The serial communications are conveniently provided through two
DB9 board mounted male connectors with adjacent LEDs indicating serial port activity.
The USB-IIRO4-2SM includes a rugged steel enclosure with attractive powder coat finish and anti-skid bottom. The unit enclosure is 4 inches
wide by 4 inches deep by 1.8 inches high. The adapter is supplied with a 6 foot USB cable. In addition to the two serial LEDs the unit features
two additional easy-to-read LEDs indicating digital I/O enabled/ready and USB power. Port protocol is configured by opening the enclosure
and configuring jumpers on the circuit board. It is fully compatible with both USB 1.1 and USB 2.0 ports. The OEM version provides just the
board without the enclosure and is ideal for a variety of embedded OEM applications.
What makes the OEM option unique is that its PCB size and mounting holes match the PC/104 form factor (without the
bus connections). This allows our rugged digital/serial board to be added to any PCI-104 or PC/104 stack by connecting it to a simple USB port usually included on-board with embedded CPU form factors such as EBX, EPIC, and
PC/104 - especially important since many newer CPU chipsets do not support ISA and have plenty of USB ports. Future stacks will be using the extremely fast PCI Express bus which is essentially overkill for simple digital monitoring
and control. The USB-IIRO4-2SM OEM board can also be added into many pre-existing standard PC/104 based systems and enclosures.
High Retention USB Connector
The ever-growing presence of USB in the industrial/military marketplace has driven the need for USB connections to be reliable, dependable,
and unfailing. Gone are the days of loose USB connections. A type B USB connector is used on all USB/104 products which features a high
retention design that complies with the class 1, Div II minimum withdrawal requirement of over 3 pounds of force (15 Newtons). This connector has an orange color-coded insulator to quickly differentiate it from standard USB connectors. Using these USB connectors increases
reliability in your system and ensures a tight connection. For embedded OEM type applications, an additional miniature USB input header is
provided in parallel with the type B connector.
The industrial I/O market commonly uses electromechanical Form C relays due to their robustness and ability to withstand unexpected surge
currents allowing for increased flexibility in switching capability. These relays are also used where small reed relays are inadequate due to
their susceptibility to contact damage. The USB-IIRO4-2SM with its tiny enclosure and easy connectivity provides portable connections to
laptops for this kind of monitoring and control for the mobile test market. The full USB-IIRO4-2SM unit can be used in the following markets.
Portable and laptop
Industrial Automation and Control
Embedded OEM
Point of Sale (POS) Retail
Data Acquisition
Serial Instrumentation
Laboratory Research
Remote Access
Advanced Digital Logic, Inc.; 4411 Morena Blvd., Suite 101; San Diego, CA 92117-4345
Ph. 858 490-0597 F. 858 490-0599; e-mail: [email protected]; web:
PC/104 - USB Isolated I/O
The USB-IIRO4-2SM is available with optional cable assemblies, screw termination boards and DIN rail mounting provisions.
The USB-IIRO4-2SM is plug-and-play which allows quick connect or disconnect whenever you need additional I/O on your USB port. The
USB-IIRO4-2SM is supported for use in most USB supported operating systems and includes a free Linux and Windows 98se/Me/2000/
XP/2003 compatible software package. This package contains sample programs and source code in Visual Basic, Delphi, C++ Builder, and
Visual C++ for Windows. Also incorporated is a graphical setup program in Windows. Third party support includes a Windows standard DLL
interface usable from the most popular application programs. Embedded OS support include Windows Xpe.
For serial communications the package includes an easy to use terminal program for testing out your COM ports. Use in other operating
systems may also be supported, contact Factory.
Block Diagram
Advanced Digital Logic, Inc.; 4411 Morena Blvd., Suite 101; San Diego, CA 92117-4345
Ph. 858 490-0597 F. 858 490-0599; e-mail: [email protected]; web:
PC/104 - USB Isolated I/O
Digital Specifications
Multidrop: Compatible with RS-485 specifications. Up to 32 drivers
and receivers allowed on line. Driver / Receivers used are type
Character Length, Parity and Stop Interval: 5,6,7, or 8 bits; Even,
odd, or none; 1, 1.5, or 2 bits
Receiver Sensitivity: ±200 mV differential input
Common Mode Voltage: +12V to -7V
Transmitter Output Drive: 60 mA with thermal shutdown
Termination: Jumper selectable per channel for RS-485 mode
Bias: On-board from factory on transmit lines for RS-485 & RS-422
Isolated Inputs
• Number of inputs: 4
• Type: Non-polarized, optically isolated from each other and from
the computer (CMOS compatible)
• Voltage Range: 3 to 31 DC or AC Rms (40 to 10000 Hz)
• Isolation: 500V*(see note) channel-to-ground or channel-to channel
• Input Resistance: 1.8K ohms in series with opto coupler
• Filter Response Times: Rise Time = 4.7 mS / Fall Time = 4.7 mS
• Non-Filter Response Times: Rise Time = 10 uS / Fall Time = 30 uS
*Notes on Isolation: Opto-Isolators and connectors are rated for at
least 500V, but isolation voltage breakdowns will vary and is affected
by factors like cabling, spacing of pins, spacing between traces on the
PCB, humidity, dust and other environmental factors. This is a safety
issue so a careful approach is required. For CE certification, isolation
was specified at 40V AC and 60V DC. The design intention was to
eliminate the influence of common mode. Use proper wiring techniques to minimize voltage between channels and to ground. For
example, when working with AC voltages do not connect the hot side
of the line to an input. Tolerance of higher isolation voltage can be
obtained on request by applying a conformal coating to the board.
Bus Type
USB 1.1 and 2.0 host compatible
Relay Outputs
Number of outputs: 4 SPDT form C
• Contact Type: Single crossbar; Ag with Au clad
• Rated Load AC: 0.5 A at 125 VAC (62.5 VA max.)
• Rated Load DC: 1A at 24 VDC (30 W max.)
• Max. Switching Voltage: 125 VAC, 60 VDC
• Max. Switching Current: 1 A
• Contact Resistance: 100 mO max.
• Contact Life: mech'l: 5 million operations min.
• Operating Time: 5 milliseconds max.
• Release Time: 5 milliseconds max.
Power Required
5V@ 120mA Quiescent, 320mA maximum
20mA for each activated relay(80 max)
0-60mA for each COM channel
+5VDC provided via USB cable up to 500mA
Operating Temperature Range: 0°C. to +60°C.
Storage temperature Range: -50°C. to +120°C.
Humidity: 5% to 95%, non-condensing.
Size: 4 inches wide by 4 inches deep by 1.8 inches high
Extra USB connections
This board has two optional USB onboard five pin connectors. One
connector allows you the added feature of connecting to a spare USB
port on the onboard USB1.1 hub. This would provide an additional,
'daisy-chained' USB 1.1 bus to which you can attach an additional
ACCES I/O USB product or any 3rd party USB devices you may wish.
Up to 180mA is still available without requiring the added device to
have its own 5VDC power source. The second five pin connector
allows the board to have an onboard USB connection rather than the
standard type B connector that is accessible externally on the encloCommunications Interface
sure. This is useful in OEM embedded or high vibration applications
• I/O Connections: There are 9 pins per port including common
grounds. All RS-232 signals are supported and present at the DB9 where a tighter fit USB connection is required than a standard USB
- RS-422 data signals – Tx+, Tx-, Rx+, Rx-, GND
Regulatory Compliance
- RS-485 data signals – 2 wire: Tx/Rx+, Tx/Rx-, GND
This product is designed to be in full compliance with CE require- 4 wire: Tx+, Tx-, Rx+, Rx-, GND
- Jumper selectable termination
• Serial Data Rates: Up to 230.4K bps, asynchronous for RS-232
• Up to 921.6K bps, asynchronous for RS-422 & RS-485.
Ordering Information
Item Codes
Enclosure and multifunction module
4 isolated digital inputs and 4 relay outputs only
2 Port USB to RS-232/422/485 serial adapter
DB25 connector external-mounted screw termination
DIN rail mounting provision
Board Only version (no enclosure)
Advanced Digital Logic, Inc.; 4411 Morena Blvd., Suite 101; San Diego, CA 92117-4345
Ph. 858 490-0597 F. 858 490-0599; e-mail: [email protected]; web: